Haven't window systems made foreground/background distinctions irrelevant to most applications, including editors?
An interesting observation. It's true that I have not used ^Z or :stop, since I've had a window system. I keep lots of terminal windows open and switch back and forth. One of the "features" of MacVIM is that when I type: vi to the command prompt, it's forked in its own (separate) window from the terminal/shell window, so the desire/need of something like ^Z for the editor that I used to need to do in my 4.XBSD days are unnecessary.
That said, if you are running on a windowless system, I can see its value. For instance, when I'm ssh'ed into a Linux box like my PiDPs, I might need to do. That said, I run VNC and a window manager on them, so needing to fall back to an ssh session is not a usual manner that I access them.
FWIW: I have nvi as the editor on my Linux boxes, as it's all I need there. But as I said, I do run MacVIM because of the integration with the Apple Windowing system.
As I also like to point out, one of my favorite features of UNIX is >>not<< being pushed into one way of doing things. UNIX often offers multiple solutions to a problem, and unlike the MSFT and, too often, the Apple world, does not try to dictate how I must do something.
As always, the editor you use is a personal choice, and I understand and accept that. It's all about what you do most effectively to do your job. What is "best" for you might not be "best" for me, and I like having a choice.
But I do think that Doug is correct, that for >>this<< particular feature, it's not clear whether it's solved in a better manner if you have a window system; but if that's how you work, go for it.